Current State of End-Game Contents - A Blog Post from A Japanese Player

[Nektulos-Tuor]

In T10, if someone dies or you mess up a mechanic, the boss gets a stack that increases the damage done by the unavoidable AoE that he does at the end of every add phase. The boss also gains stacks during the add phase, so if you don't kill the adds fast enough, you can end up with a wipe.

The final phase also has three different sets of mechanics that happen at random, each one requiring a different method of handling them. There's a loose pattern in the sense that you won't get two Wild Charges combos in a row, but other than that, there's no set rotation for them..

That isn't a buff like I described, that is simply someone missing the script. That usually means you wipe, its not dynamic. It happened because someone didn't follow the script. Its the same as if you didn't kill the adds in Striking Tree, if you don't we all die.